Consistent with the increasing trend toward recycling or various types of containers, such as aluminum and plastic containers, various forms of container counting apparatus are being utilized during the course of reclaiming such recycleable containers. Such counting apparatus is particularly useful in geographical areas where container vendors must refund previously collected deposits for each returned empty container. Under these circumstances the vendor may accumulate a large number of empty containers which are then sold to a reclaimer who crushes and bales or otherwise conditions the containers for subsequent handling.
At various stages of the foregoing procedures, it is necessary to provide some manner of ascertaining the total number of containers being processed. While various systems of counting containers are available, one such system advantageously utilizes apparatus which is capable of automatically counting containers in a continuous and effective manner. Such system is disclosed in U.S. Pat. No. 4,590,364, issued May 20, 1986. This apparatus includes a counting unit which is provided with a movable conveyor having a plurality of parallel and spaced partitions or dividers overlying such conveyor to provide a series of parallel pathways or lanes leading toward a discharge zone. A container metering device is provided upstream from the discharge zone and overlies the lanes and functions to preclude stacking of such containers so that no more than one container in any lane may pass the metering device at any one time.
A counting mechanism is provided at the discharge zone which functions to count and record the number of containers discharged from such zone. The use of photoelectric sensors is specifically disclosed in the aforesaid patent, such sensors being of the type which generate a counting pulse in a counting mechanism each time a light beam is established between the emitter and collector of each sensor.
Although the aforesaid container counting apparatus is highly efficient in the counting of opaque containers, it is not readily adaptable to the counting of different kinds of containers, particularly empty bottles formed of transparent plastic. Photoelectric counting means will not function efficiently with transparent plastic containers because the light beam is readily transmitted through the container. When confronted with a series of transparent containers, the photoelectric counting arrangement is incapable of distinguishing each individual container and the resultant total count is inaccurate.
Some plastic containers, usually in the form of bottles include opaque areas caused by labels or areas of different types of plastic. A photoelectric counting mechanism is incapable of accurately distinguishing one such container from another and, on occasion, the presence of a label or different kinds of plastic material may result in a photoelectric counting mechanism to provide a multiple count for a single container, thereby causing overall inaccuracy in the count.